Installation or device with a high-definition multimedia interface

ABSTRACT

The Installation is equipped with a power supply unit and a High-Definition Multimedia Interface (HDMI), this installation being able to be connected to a second HDMI device with which it can communicate by using a protocol defined in the HDMI Standard, this installation or device being able to be set in Standby or Power-down mode and to be removed from this Standby or Power-down mode by said second HDMI device via a Consumer Electronic Control (CEC) line. The installation has a Power Management Unit (PMU) arranged on the primary side of said power supply unit, this PMU having its own power supply circuit directly connected to the power supply source of this installation or device and being arranged for switching OFF the electrical energy on the secondary side of said power supply unit when this installation or device enters said Standby or Power-down mode.

FIELD OF THE INVENTION

The invention concerns an electrical installation or device having apower supply equipped with a voltage converter or transformer and aHigh-Definition Multimedia Interface (HDMI).

In particular, the invention may be implemented in audio/video consumerelectronic devices equipped with HDMI functionality, such as a digitalTV set, a display or a computer screen, a DVD player, a decoder or ademodulator (Set-Top Box), in entertainment devices like electronic playstations, etc.

BACKGROUND OF THE INVENTION

Systems with high speed, high quality audio/video interfaces have beenoffered in the market since shortly after the release of the HDMIstandards around 2002.

The general structure of such an HDMI is shown in FIG. 1. Video andaudio information is transmitted between a “source” part 2 of a firstdevice having a HDMI transmitter 4 (e.g. DVD player, a set top box) anda “sink” part 6 of a second device having a HDMI Receiver 8 (e.g. adisplay, a digital TV) over the data and signal buses TMDS Channel 0,TMDS Channel 1, TMDS Channel 2 and TMDS Clock Channel. System displayinformation is exchanged over the Display Data Channel (DDC). Operatingmodes (including entering and leaving Standby mode) of multiple devicesare controlled and associated protocol messages are exchanged over theCEC (Consumer Electronic Control) line 10.

A typical system comprising multiple devices (in particular digital TV12, DVD player 18 and Set Top Box 22) connected via HDMI is shown inFIG. 2. The system has a given architecture with different levelsreflected by the Physical Address (PA). On the first level are the SetTop Box 22 and a PC Game Box 24 both connected to a switcher 20. Thisswitcher defines a second level with the DVD player 18, both beingconnected to an Audio-Video Recorder (AVR) 16. This AVR is connected toa recording device 14 which is finally connected to the Digital TV 12. Asingle CEC control line connects all system devices and a determined CECProtocol allows these devices to communicate one to another, this CECProtocol being included as an optional part of the HDMI Standard.Individual devices are identified by physical (PA) and logical (LA)addresses that are used for allowing a first device to exchange commandswith a determined second device.

Decoding of CEC protocol and embedded commands is performed in eachdevice connected to the CEC line 10. The CEC line is thereby connectedto a physical CEC interface 30 arranged in each device followed by adecoder or more generally a CEC Controller 32 as shown in FIG. 3. From apower supply perspective, standard HDMI-equipped systems implement powersupply topologies that rely on the use of power supply subsystems ormodules whereby system interfaces, system processors and displayelements are powered by the secondary side of a converter. The CECinterface 30 of a first HDMI device, in particular a sink device, can besupplied by the secondary part of a second HDMI device, in particular asource device. The CEC interface is usually supplied with a voltage of 5V. Thus, the source device which sends a command to a sink device underthe CEC Protocol also provides the necessary electrical energy forsupplying the CEC Interface of this sink device.

In the Standby mode of a conventional HDMI installation or device atleast the CEC interface 30, the CEC controller 32 and also correspondingportions of the main system processor 34 are supplied and able tooperate. The CEC controller and the system processor of each HDMI deviceare supplied by the secondary part 38 of the power supply unit 36 whichis equipped with a voltage converter. The primary part 40 of thisvoltage converter is usually connected to the mains. FIG. 3schematically represents a digital TV with a display 44 also supplied bythe power supply unit 36. It is to be noted that this display can haveits own power supply unit or use a dedicated part of the power supply36.

In order for a first HDMI device to be removed or woken up from aStandby or Power-down mode by a second HDMI device with the help of theCEC Protocol, the first HDMI device has in the present technology thesecondary part of its power supply unit at least partially supplied forsupplying at least the CEC Controller. Thus, the power consumption inthe Standby or Power-down mode remains relatively high first because theprimary side of the power converter is supplied in this mode andsecondly also because a part of the electronic circuits on the secondaryside of this power converter needs to be supplied for allowing thereception, decoding and processing of at least a wake-up signal sentunder the CEC Protocol, i.e. a command sent by another HDMI device.

A very low energy consuming power supply architecture is disclosed inthe document WO 2010/003785. It outlines an efficient power managementin Standby or Power-down mode. This power supply comprises a converterdefining a primary side and a secondary side for the device equippedwith it. A Power Management Unit (PMU) is arranged on the primary sidewith its own secondary energy supply circuit directly linked to themains. This PMU is associated with a control circuit of the converterfor setting OFF this converter in a Power-down mode, in order to have avery low power consumption. However, in this Power-down mode, there isno supply of the secondary side of the converter. As a consequence, sucha system cannot be used with above described standard HDMI deviceshaving a CEC line allowing a first device to wake up a second devicelinked to this first device by an HDMI.

SUMMARY OF THE INVENTION

Cumulative stand-by power consumption of HDMI equipped audio/videodevices is increasing and will be very large in a near future. Thus,there is a large energy savings potential by reducing this electricalconsumption to the lowest level. Since operating an HDMI involves atleast two and in many cases several devices and systems, the standbyenergy consumption is multiplied accordingly.

A main object of the present invention is to reduce the powerconsumption of HDMI devices in Standby or Power-down mode.

The invention thus concerns an installation or device equipped with apower supply unit and a High-Definition Multimedia Interface (HDMI),this installation or device being able to be connected to a second HDMIdevice with which it can communicate by using a Protocol defined in theHDMI standard (HDMI Protocol), this installation or device being able tobe set in Standby or Power-down mode and to be removed from this Standbyor Power-down mode by said second HDMI device via a Consumer ElectronicControl (CEC) line. This installation or device is characterized inthat:

it has a Power Management Unit (PMU) arranged on the primary side of thepower supply unit, this PMU having its own power supply circuit directlyconnected to the power supply source of the installation or device andbeing arranged for switching OFF the electrical energy on the secondaryside of said power supply unit when this installation or device enterssaid Standby or Power-down mode;

the PMU is associated with CEC means on said primary side for decodingand processing at least a wake-up signal of a CEC Protocol defined insaid HDMI Standard;

it comprises a CEC interface which is arranged for directlycommunicating with said CEC means on said primary side; and

the CEC interface comprises a HDMI supply domain and a PMU supply domainwhich are isolated from each other by a galvanic isolation, a datatransfer between these HDMI and PMU domains via the CEC line beingoperated only through one or several non-galvanic element(s).

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will further be described in more detail in thefollowing description with the help of the drawings, given as examplesin a non-limiting way, in which:

FIG. 1, already described, schematically shows a standard HDMIstructure;

FIG. 2, already described, schematically shows a typical systemcomprising multiple devices connected via HDMI;

FIG. 3, already described, schematically shows a standard architectureof a HDMI digital TV;

FIG. 4 schematically shows a first embodiment of a HDMI digital TVaccording to the present invention;

FIG. 5 schematically shows a second embodiment of a HDMI digital TVaccording to the present invention; and

FIG. 6 shows a preferred embodiment of the CEC interface according tothe present invention.

DETAILED DESCRIPTION

The architecture diagram of a first embodiment of an installation ordevice according to the present invention is shown in FIG. 4. Moreparticularly, this FIG. 4 represents a HDMI digital TV. The supply ofthe display 44 can be made by a specific converter and associatedcircuits.

According to this first embodiment, the CEC controller is arranged onthe converter primary side 52 of the power supply unit 50 and controlsall CEC communication between the corresponding HDMI device and otherHDMI devices of the system. In a preferred variant, the electricalsupply of this CEC controller is provided, at least in Standby orPower-down mode, through the secondary power supply of the PowerManagement Unit (PMU) arranged on the primary side of the converter, asdescribed in document WO 2010/003785 which is enclosed by reference inthe present description. Thus, this variant has no CEC controller on thesecondary side of the power unit but a CEC controller incorporated in a“PMU & CEC controller” electronic part 56 on the primary side whichremains power supplied in Standby and Power-down mode. In a particularvariant, the CEC controller is at least partially incorporated in theMicro-Controller Unit (MCU) of the PMU which is specifically arrangedfor decoding and processing CEC commands and data. The CEC line of theCEC Interface 58 is thus no more connected to a unit supplied by thesecondary side 54 of the converter forming the power supply unit 50 butto a unit supplied by the primary side 52 of this converter, what is notconventional for a person skilled in the art. A preferred embodiment ofthis CEC Interface 58 will be described later on.

When the system processor 34 is active, i.e. when the device is not inthe Power-down mode and this system processor is power supplied by theconverter secondary side 54, CEC commands and data not directly relatedto power management in a first variant or to the Power-down mode in asecond variant are transmitted to the system processor 34 through astandard communication protocol such SPI, I2C, UART. Opto-couplerelements are provided in the signal path/on the signal line between theCEC controller and the system processor located on the secondary side ofthe power supply unit. CEC commands related to power-up or power-downare directly processed by the PMU, in order to switch ON or OFF theconverter secondary side 54. CEC address allocation is also handled bythe CEC controller on the converter primary side.

A second embodiment of an installation or device according to theinvention is shown in FIG. 5. A CEC receiver is arranged on the primaryside 64 of the converter in the PMU supply domain and forms with the PMUa “PMU & CEC Receiver” electronic part 62. A further CEC controller 66is arranged on the secondary side 54. The CEC receiver and the CECcontroller both are connected to the CEC interface 68. The CEC receivercan receive power management commands coming from another HDMI devicethrough the CEC interface 68 and it only handles such power managementcommands and also a “CEC address allocation” command. In a particularvariant, it handles only commands requiring to power up or power downthe secondary side 54 of the power supply unit 60 further to said “CECaddress allocation” command. The power management commands handled bythe CEC receiver are then processed by the PMU. The CEC and the PMU canbe formed as a same electronic unit processing the CEC commands andmanaging at least power-up or power-down signals. As in the firstembodiment, the CEC receiver can be at least partially incorporated inthe MCU of the PMU.

The CEC controller 66 on the secondary side reacts to all other commandsin active mode and also to the “CEC address allocation” command. ThisCEC controller 66 is similar to conventional CEC controllers and isdirectly connected to the CEC interface 68. The CEC receiver on theprimary side and the CEC controller on secondary side must have the sameaddress with the present CEC Protocol. It means that when a “CEC addressallocation” command is handled both CEC receiver and controller shallset the given logical and physical CEC address.

A preferred embodiment of the CEC interface 58 of the first embodimentof the installation or device described here-before is shown in FIG. 6.On one side there is the HDMI supply domain which is powered by the +5 Vsupply line defined as part of the HDMI standard connector. The ground(GND) connection in this domain is formed by the CEC/DDC line. The CECline 70 supplies the data for the CEC protocol. On the other side thereis the PMU supply domain which is supplied directly by the mains on line“VSUP” and the corresponding ground line GND. A PMU & CECMicrocontroller 72 (MCU) is directly supplied from the mains (HighVoltage) via its own secondary power supply 74 including one or morevoltage reducer(s). A detailed description of such a secondary powersupply for a MCU is given in the document WO 2010/003785 which isenclosed by reference in the present description. It is to be noted thatthe circuit on the PMU Supply domain (R2, 76, 78, NM1 and R3) canadvantageously in a further variant be power supplied through anintermediate level of the secondary power supply 74 providing anintermediate voltage, e.g. 12 V.

According to the invention, the HDMI supply domain and a PMU supplydomain are isolated from each other by a galvanic isolation, a datatransfer between these HDMI and PMU domains being operated only throughone or several non-galvanic element(s). This is an important feature ofthe CEC interface according to the present invention, because thisgalvanic isolation protects the HDMI supply domain from a High Voltageprovided to the primary side of the converter (50; 60). This protectionis particularly useful for protecting the source unit because the HDMIsupply domain of the device or installation is galvanically connected tothe secondary part of the converter of such a source unit. Thus, in thefirst embodiment of the invention, such galvanic isolation does notprotect the device or installation itself (sink unit, e.g. a digital TV)but the source unit (e.g. a DVD player) to which the device orinstallation of the invention is electrically connected. In the variantof FIG. 6, two opto-couplers 76 and 78 are arranged for transmittingdata in both communication directions. Without such a galvanic isolationthe phase wire from the mains could be directly connected to GND (PMU).If we connect GND (PMU) to GND (HDMI) via a galvanic path, the phasewire could be connected to the ground of the HDMI cable which is, from asafety point of view, dangerous.

The CEC protocol is very slow and can be handled by a MCU of moderatecomputational performance. Frequency is generally 400 Hz. By default,when no device communicates on CEC line 70, the CEC voltage is at +5 V.This voltage is guaranteed by pull-up resistor R1 on the HDMI domainside. Each device connected to CEC line 70 has such resistor. The valueof this resistor is defined in the CEC specification: 27 kOhm +/−5% or26 kOhm +/−10% when integrated. The CEC protocol consists of sendingserial encoded bits as follows: logical ‘0’ consists of driving the CECline to 0 V (CEC/DDC GND) during 1.5 ms and release to +5 V with thehelp of the pull-up resistor during 0.9 ms. Logical ‘1’ consists ofdriving the CEC line to 0 V (CEC/DDC GND) during 0.6 ms and releasing itto +5 V with the help of the pull-up resistor during 1.8 ms. In bothcases the bit transmission duration is 2.4 ms. Sampling is done in awindow of +/−0.2 ms around 1.05 ms after first falling of CEC line.

The MCU 72 in the PMU supply domain receives data from the CEC line 70on input E1 through the opto-coupler 76 (OPTO1) and transistor PM1. Whenthe voltage on CEC line 70 is at +5 V (logical level ‘1’) the transistorPM1 is non-conductive, the LED in OPTO1 is OFF and then the bi-polarelement in OPTO1 is non-conductive. Due to the pull-up resistor R2logical level on E1 is at ‘1’. When the CEC line 70 is at 0 V (logicallevel ‘0’) the transistor PM1 is conductive, the LED in OPTO1 is ON andthen the bi-polar element in OPTO1 is conductive. This bi-polar elementforces E1 at logical level ‘0’.

The MCU 72 in the PMU supply domain sends data to the CEC line 70 in E2through the transistor NM1 and the opto-coupler 78 (OPTO2). When E2 isat logical level ‘1’ the transistor NM1 is conductive, the LED in OPTO2is ON and then the bi-polar element in OPTO2 is conductive and forcesCEC line to 0 V (logical level ‘0’). When E2 is at logical level ‘0’ thetransistor NM1 is non-conductive, the LED in OPTO2 is OFF and then thebi-polar element in OPTO2 is non-conductive. Thus, CEC line 70 is at +5V (logical level ‘1’) due to the pull-up resistor R1.

The HDMI specifications call for a maximum leakage current of 1.8 μA onthe CEC line toward CEC/DDC_GND when the system is powered OFF. Theopto-coupler OPTO2 has to be OFF even if the voltage supply VSUP isfloating. R3 ensures that the transistor NM1 is OFF when no power issupplied to VSUP.

It is to be noted that a same CEC interface can be implemented in theCEC Interface 68 of the second embodiment of an installation or devicepreviously described for the communication toward the “PMU & CECreceiver” electronic part 62 (FIG. 5). Such a CEC interface can bearranged in parallel with a standard interface with the CEC controller66. Other variants for the CEC interface 68 can be provided by a personskilled in the art wherein both interfaces to the CEC receiver andcontroller are combined.

A specific application of the present invention, based on the secondembodiment of an installation or device previously described, isoutlined on the example of wake-up and standby operations of aHDMI-equipped DVD player. Waking up such a DVD player is achievedthrough the HDMI-defined CEC protocol. In the low power mode (Standby orPower-down mode) only the “PMU & CEC Receiver” electronic part issupplied while the rest of the system is not powered. The correspondingMCU receives commands over the CEC interface to wake up the DVD player.In this case the “PMU & CEC Receiver” MCU uses the same CEC logical andphysical address as the DVD player main system processor (LA=4,PA=1.1.2.0). In the Power-down mode this MCU decodes the CEC protocoland reacts to CEC events that require action and/or a response from theDVD player (e.g. the “standby” or “play” commands). If such a decodedmessage requires the DVD player to move from its low power mode to anactive mode the “PMU & CEC Receiver” MCU starts up the power converterto supply the elements on the converter secondary side for operation.

1-9. (canceled)
 10. An installation or device equipped with a powersupply unit and a High-Definition Multimedia Interface (HDMI), saidpower supply unit comprising a converter defining a primary side and asecondary side, this installation or device being able to be connectedto a second HDMI device with which it can communicate by using aprotocol defined in the HDMI Standard, this installation or device beingable to be set in Standby or Power-down mode and to be removed from thisStandby or Power-down mode by said second HDMI device via a ConsumerElectronic Control (CEC) line, wherein the installation or device has aPower Management Unit (PMU) arranged on the primary side of said powersupply unit, this PMU having its own power supply circuit directlyconnected to the power supply source (VSUP) of the installation ordevice and being arranged for switching OFF the electrical energy on thesecondary side of said power supply unit when this installation ordevice enters said Standby or Power-down mode, wherein said PMU isassociated with CEC means on said primary side for decoding andprocessing at least a wake-up signal of a CEC Protocol defined in saidHDMI Standard, wherein it comprises a CEC interface which is arrangedfor directly communicating with said CEC means on said primary side, andwherein said CEC interface comprises a HDMI supply domain and a PMUsupply domain which are isolated from each other by a galvanicisolation, a data transfer between these HDMI and PMU domains via saidCEC line being operated only through one or several non-galvanicelement(s).0
 11. The installation or device according to claim 10,wherein said CEC interface comprises two opto-couplers used for abidirectional communication between said CEC means on said primary sideand said second HDMI device.
 12. The installation or device according toclaim 10, wherein said CEC means on said primary side are formed by aCEC controller which receives from said CEC interface and processes allcommand signals of the CEC Protocol, this CEC controller being connectedto a system processor on said secondary side to which it transmits atleast commands and data not directly related to power management of theinstallation or device.
 13. The installation or device according toclaim 11, wherein said CEC means on said primary side are formed by aCEC controller which receives from said CEC interface and processes allcommand signals of the CEC Protocol, this CEC controller being connectedto a system processor on said secondary side to which it transmits atleast commands and data not directly related to power management of theinstallation or device.
 14. The installation or device according toclaim 10, wherein said CEC means on said primary side are formed by aCEC receiver which is arranged for receiving and handling a “CEC addressallocation” command and further at least commands requiring to power upor power down the secondary side of the installation or device in orderto enter, respectively to be removed from said Power-down mode.
 15. Theinstallation or device according to claim 14, wherein it furthercomprises a CEC controller on said secondary side, this CEC controllerand said CEC receiver being both directly connected to said CECinterface.
 16. The installation or device according to claim 11, whereinsaid CEC means on said primary side are formed by a CEC receiver whichis arranged for receiving and handling a “CEC address allocation”command and further at least commands requiring to power up or powerdown the secondary side of the installation or device in order to enter,respectively to be removed from said Power-down mode.
 17. Theinstallation or device according to claim 12, wherein said CEC means onsaid primary side are formed by a CEC receiver which is arranged forreceiving and handling a “CEC address allocation” command and further atleast commands requiring to power up or power down the secondary side ofthe installation or device in order to enter, respectively to be removedfrom said Power-down mode.
 18. The installation or device according toclaim 13, wherein said CEC means on said primary side are formed by aCEC receiver which is arranged for receiving and handling a “CEC addressallocation” command and further at least commands requiring to power upor power down the secondary side of the installation or device in orderto enter, respectively to be removed from said Power-down mode.